Internal combustion engines are still the predominant means for propelling motorized vehicles. They are proven to offer many advantages over alternative mechanisms, among these being cost and convenience. Such engines require lubrication, usually employing a circulating lubricant such as oil. Filter assemblies are commonly used to filter the oil to remove contaminants, thereby protecting a combustion engine and preventing damage to the engine and its components lubricated by the oil.
A by-product of combustion is the generation of acids in the ring zone of the engine. Acids can degrade the quality of the oil and shorten oil drain intervals, and if the oil is not changed, can reduce the intended effectiveness of the oil thereby leading to engine damage or failure.
The concept of immobilizing a strong base in a filter assembly and using the strong base to neutralize engine generated acids has been known since the early 1900's. The intent of this known technology is to extend oil drain intervals without changing oil additive package chemistry. It is believed that this technology works in the following manner. As acids are generated in the ring zone of the engine, a weak base will form an acid-base pair with the acid and carry it away from the ring zone to the filter assembly. In the filter assembly, the immobilized strong base will “grab” the acid away from the weak base forming an acid-base pair that is trapped by the immobilized strong base. The weak base is then free to react with more acids in the ring zone, carrying them back to the immobilized base.
However the immobilized base technology may only work with a very select few weak bases. Therefore, the immobilized base technology alone may not work “across the board” for all ail formulations.